You must set workflow credentials if you are running actions in a secured cluster. You
set the credentials at the global level, then select the user when you create or edit an
action node.

Some action types talk to external services such as HCatalog, HBase Region Server, and
Hive Server 2. In these circumstances, extra configuration is required to authenticate.
Kerberos credentials are used to obtain delegation tokens on behalf of the user from the
external service.